1. Field of the Invention
The present invention relates to a sensor network and method for establishing a data transmission path. More particularly, the present invention relates to a sensor network and method for establishing a data transmission path, which can efficiently establish the data transmission path from a data transmitter to a data receiver that is even in motion.
2. Description of the Related Art
A general mobile communication system transmits and receives data between a mobile terminal and a base station. The mobile terminal and the base station directly transmit and receive data with each other, not through any other mobile terminals/nodes.
However, a sensor network uses other nodes in order to transmit data to a sink node (data transmitter). In other words, nodes constituting the sensor network include a sink node, a source node, and a relay node depending on their functions. The sink node, which serves as a data receiver, is a destination node to which specified data are to be transmitted. The source node, which serves as a data transmitter, is an originating node of the specified data to be transmitted to the sink node. Meanwhile, the relay node means a node constituting a data transmission path from the source node to the sink node.
The source node located within a predetermined distance from the sink node directly transmits data to the sink node. However, the source node, which is not located within the predetermined distance from the sink node, does not directly transmit data to the sink node but transmits the data to the relay nodes adjacent to the sink node. This is to minimize power consumption caused by data transmission. In other words, the distance between the sink node and the source node is generally proportional to power consumption required to transmit data from the source node to the sink node.
Therefore, the source node, which is not located within a predetermined distance from the sink node, transmits data using a plurality of relay nodes so as to minimize power consumption caused by data transmission. However, the sink node is not fixed but is somewhat movable.
FIG. 1 illustrates the principle of a conventional method for establishing a data transmission path. Referring to FIG. 1, in case where the sink node moves from a first position 10 to a second position 20, a path loss occurs in an originally established path due to a movement of the sink node as shown in steps 2 and 1 respectively, and a new path is established to recover such a path loss, step 3.
However, the conventional method for establishing a data transmission path has the problem that a path is newly established when the path loss occurs due to the movement of the sink node. In other words, a problem arises in that the existing information on the data transmission path is not used in establishing a new path.
Accordingly, there is a need for an improved sensor network and method for establishing a data transmission path.